Apparatus for manufacturing mineral wool fibers



Aug. 14, 1962 M. s. FIRNHABER ET AL APPARATUS FOR MANUFACTURING MINERAL WOOL FIBERS Filed April 1. 1960 BY Mass 5. FIRNHABER. 7% firrofiA/izs'.

trrt

3,048,88fi Patented Aug. 14, 1962 fifice This invention relates to an improved apparatus for manufacturing mineral wool fibers and the like, and more particularly to an improved fiber-producing apparatus including a rotor constructed entirely of metal.

In the operation of fiberizing apparatus, molten glass or similar thermoplastic material is thrown from a rapidly spinning rotor by centrifugal force and acted upon by a blast of steam or other fiberizing agent to produce the thin fibers used in mineral wool and similar products. Heretofore, the molten material receiving portions of such rotors have customarily been constructed of a ceramic or refractory insulating material, in order that the molten glass deposited thereon could be maintained at a stiflic-iently high temperature during the fiberizing operation. It was thought that a rotor formed of metal could not withstand the intense heat required and that there would be a rapid deterioration of the structural integrity of the metal, necessitating frequent and costly replacement of the rotor. It has been found, however, that rotors formed of ceramic materials are also subject to definite objections. Such ceramic materials tend to dry out and crack in a relatively short time, and in addition, the fiber-forming surfaces of such rotors are quickly worn away by the erosive action of the molten glass.

With the above considerations in mind, one of the principal objects of the present invention is to provide a fiberizing apparatus for use in manufacturing mineral W001 and the like, wherein the rotor is formed of a hard, wear-resistant metal alloy, there being means therein for cooling the rotor during the fiberizing operation in order to prevent structural deterioration of the metal.

A further object of the present invention is to provide a rotor assemblage wherein the components can be separately detached and replaced in the event they become worn or broken, thereby eliminating the necessity of replacing the entire rotor.

A further object is to provide a fiberizing apparatus having molten material delivery means adapted to partially separate and attenuate the material before it is deposited on the rotor, thereby promoting complete fiberization and minimizing the occurrence of imperfect fibers or slugs in the finished product.

A further object of the present invention is to provide a fiberizing apparatus wherein the temperature and viscosity of the molten material can be effectively controlled during the fiberizing operation, thereby insuring that the fibers produced are of a consistently fine variety.

Further objects of the present invention are to provide a fiberizing apparatus as above described which is relatively simple in design and construction, which is efiicient .in operation, and which is capable of producing an unusually high quality product.

With the above and other objects in view, the invention consists of the improved fiberizing apparatus for use in manufacturing mineral wool and the like, and all of its parts and combinations as set forth in the claims, and all equivalents thereof.

In the accompanying drawing, illustrating one complete embodiment of the preferred form of the invention, and wherein the same reference numerals designate the same parts in all of the views:

FIG. 1 is a view, principally in vertical section, of the fiberizing apparatus comprising the present invention;

FIG. 2 is a top plan view of the rotor, taken along line 2-2 of FIG. 1;

FIG. 3 is a fragmentary top plan view of the annular rim member employed in the present invention;

FIG. 4 is a sectional view of said annular rim taken along lines 4-4 of FIG. 3; and

FIG. 5 is a plan view of one of the spacing washers employed in the invention.

General Operation In the general operation of a fiberizing apparatus as shown, molten glass or other like material is delivered from the melting furnace by a tube 13 (FIG. 1 of the drawing) and deposited thereby onto the dished upper surface of a rapidly-spinning rotor, which is designated generally by the numeral 35. Hot gases or flames 21 are constantly directed against said rotor top surface by means of burners 20 to maintain the molten material at a proper temperature and viscosity, and a hood 23 is provided to prevent outside air from contacting and prematurely cooling the material. The molten material is flung from the periphery of the rotor by centrifugal force, in the form of individual filaments which are acted upon by the serrations on the rotor periphery, and as said filaments leave the rotor they are intercepted by a high velocity blast 32 of preheated air, gas, or steam emitted from a ring 25 mounted above said rotor. The direction of the filaments is abruptly changed by said jets, and the filaments are attenuated thereby into the fine fibers required in mineral wool and similar products.

The Structure Unlike conventional rotors, which are formed at least partly of ceramic or refractory insulating material, the rotor comprising the present invention is formed entirely of metal, which is made possible by a novel cooling systern which will be hereinafter described. It has been found that an alloy consisting of chromium, nickel, and cobalt is very satisfactory but other metals or alloys might be preferred for certain purposes and the particular metal employed is not critical to the invention.

Referring now more particularly to FIG. 1 of the drawing, the improved rotor assemblage includes a generally cylindrical base member 37 positioned below the lower end of the delivery tube 13 and operatively mounted on a drive shaft 36. Mounted on and in spaced relation above said base member is a rotor head 39 having a dished top surface 4-2 adapted to receive the molten material and having a plurality of radial grooves 43 to promote the formation of the material into filaments as the same moves toward the rotor periphery. Said rotor head and base members 39 and 37 are separably connected by bolts 49, and a number of washers 41 are interposed between said rotor members to maintain the same in their spaced relation. The spaced mounting of said rotor members permits cooling air to pass therebetween during operation to prevent overheating and is, of course, an important feature of the invention. In addition, and as will be seen in FIG. 5, the washers 41 interposed between said rotor base and head members are formed with peripheral projections 51 which are designed to function as small fan blades as the apparatus rotates to promote the circulation of air between said members. Air also circulate below the rotor part 39 in the hollow chamber which has holes 61 communicating with the exterior.

Referring again to FIG. 1, it will be seen that not only are the metal rotor base 37 and head member 39 mounted in spaced relation, to promote cooling as described, but the rotor head is formed with a plurality of channels 53 span-see extending horizontally therethrough to carry heat from the rotor interior outwardly to the atmosphere, thereby further lessening the possibility of overheating and deterioration of the metal.

Surrounding the rotor head 39 is an annular rim 45 of a larger diameter than the external diameter of said rotor head, there being an air space 46 therebetween, which rim is removably secured to the rotor by means of specially-designed bolts 47 having longitudinal openings 48 therethrough. In addition to securing the rim 45 in place on the rotor head, said hollow bolts also function to convey heat outwardly from the rotor interior.

The inner surface of the rim member 45 is provided with spaced, obliquely-angled blades 49 (FIGS. 3 and 4), and the upper edge 50 of said rim has a multiplicity of serrations. In the operation of the rotor, said angled blade members 49 on the rim inner surface provide a fan action to draw air through the rotor cooling channels and to forcibly direct heat from around the rotor upwardly through the annular space 46. As the molten material filaments leave the periphery of the rotor as hereinbefore described, they are intercepted by said current of hot air and precooling of said filaments is prevented prior to their engagement by the steam jets 32. In addition, said upwardly directed air currents from the fan blades 49 in the annular space 46 function to lift the filaments sufficiently to insure that they pass over the serrated edge Silof said annular rim member where they are acted upon by the serrations to aid in obtaining a desirable fineness of product. It has been found that said rim serrations substantially outlast the serrations on the rotor proper, and remain effective even after the rotor surface has become worn or eroded, thereby increasing the life of the apparatus and enhancing its utility.

As' hereinbefore mentioned, the improved apparatus is also provided with special means for separating the molten material into a multiplicity of individual streams before the same is fed onto the rotor, to enhance the fiberization of the material. In this respect, and referring to FIG. 1 ofthe drawing, formed in the center of and projecting upwardly from said rotor top surface is a dome 44, there being any open-top, bowl-like member 33 mounted'on its upper end portion, the lower margin of said bowl being provided with a multiplicity of downwardly angled apertures 34. The lower open end of the delivery tube-13 projects into said bowl 33 and is positioned to discharge the stream of molten material 52 onto the dome 44, the material being thrown thereby through the downwardly angled apertures 34 onto the dished upper surface 42 of the rotor. Said coacting dome and bowl units not only promote the even and uniform distribution of the molten material on the surface of the rotor, but the passage of said material through the apertures 34 preforms the material into individual streams and minimizes the possibility of uniformed globules or slugs in the finished product.

Summary From the foregoing detailed description, it will be appreciated that the present invention provides an improved apparatus for manufacturing glass fibers or the like having several new and advantageous features. First, due to the novel cooling system incorporated therein, the entire apparatus comprising the present invention may be formed of metal, and it is no longer necessary to employ ceramic or other refractory insulating materials which are quickly worn or deteriorated by the intense heat and erosive action of the molten glass. By substituting metal for a refractory material, a hard, wear-resisting surface is provided and the useful life of the apparatus is sub stantiallyincreased. Secondly, the present improved apparatus 'has means thereon for separating and attenuating the molten material before the same is deposited on the rotor, thereby ensuring the production of high quality fibers.

A further advantage in the improved apparatus is provided by the serrated annular rimmember which, in addition to being part of the rotor cooling system, also functions as a supplementary fiber attenuating means which will last longer than the grooves 43 on the rotor proper. Finally, the fact that the component parts of the present structure can be separately detached and replaced eliminates the necessity for removing and replacing the entire apparatus in the event of damage, and contributes to the increased utility of the invention.

It is to be understood that variations or modifications of the apparatus hereinabove described may suggest themselves to those skilled in the art, and all of such variations or modifications are contemplated as may come within the scope of the following claims.

What we claim is:

1. A metal rotor for use in a fiberizing apparatus, comprising: a rotatably mounted base; a rotor head mounted on and spaced above said base and having a peripheral wall of substantial depth, said rotor head having interior cooling channels extending to said peripheral Wall; a rim surrounding said peripheral wall of the rotor head and rotatable therewith, there being an annular space therebetween; and fan means on said rim in said annular space for drawing air through said rotor head cooling channels into said annular space.

2. A metal rotor for use in a fiberizing apparatus, comprising: a rotatably mounted base; a rotor head mounted on and spaced above said base and having a periphery; a plurality of spacing members interposed between said base and rotor head near the periphery of the latter to maintain the same in spaced relation; and peripheral projections on said spacing members forming fan blades when the rotor is in operation.

3. In a fiberizing apparatus, a metal rotor structure comprising: a rotatably mounted base; a rotor head mounted on and spaced above said base and having a peripheral wall of substantial depth, said rotor head having interior cooling channels extending to its peripheral wall; spacing members interposed between said base and rotor head near the periphery thereof to maintain the same in spaced relation, said spacing members having peripheral projections thereon forming fan blades when the rotor is in operation; a rim surrounding the periphery of said rotor head and rotatable therewith, there being an annular space therebetween; and fan means on said rim in said annular space to draw air through said rotor head cooling channels into said space.

4. In a fiberizing apparatus, a metal rotor structure comprising: a rotatably mounted base; a rotor head mounted on and spaced above said base, said rotor head having a dished, molten material receiving upper surface with a multiplicity of fiber-forming peripheral serrations; a rim surrounding said rotor head, there being an annular space therebetween, said rim fixed to said rotor for rotation therewith and having a multiplicity of fiber-forming serrations on its upper edge; and means on said rim providing a fan action when the rotor is in operation to dissipate heat from around said rotor.

5. In a fiberizing apparatus, a metal rotor structure comprising: a rotatably mounted base; a rotor head mounted on said base having a dished, material-receiving top surface; a dome projecting upwardly from the dished top surface of said rotor head; and a bowl mounted on an intermediate portion of said dome spaced above said material-receiving surface to receive molten material deposited on said dome and having apertures therethrough arranged to direct the molten material onto the top surface of said rotor head in a plurality of individual streams.

6. In a fiberizing apparatus including a delivery member for molten material leading from a melting furnace and having a lower discharge end, a metal rotor structure comprising: a base rotatably mounted below said delivery member lower discharge end; a cylindrical rotor aosaase head mounted on and spaced above said base, said rotor head having a plurality of cooling channels therethrough and a dished molten material receiving upper surface; an annular rim surrounding said rotor head, there being an annular space therebetween, said rim having a serrated top edge; a plurality of spaced obliquely angled fan blades on the inner surface of said rim; and a plurality of hollow bolts securing said rim to the rotor head.

7. In a fiberizing apparatus including a delivery member for molten material leading from a melting furnace and having a lower discharge end, a metal rotor structure comprising a base rotatably mounted below said delivery member lower discharge end; a cylindrical rotor head mounted on and spaced above said base, said rotor head having a plurality of cooling channels therethrough and a molten material receiving upper surface; spacing members interposed between said base and rotor head to maintain the same in spaced relation, said spacing members having peripheral projections thereon forming fan blades when the rotor is in operation; an annular rim surrounding said rotor head, there being an annular space therebetwecn, said rim having a serrated top edge; a plurality of spaced obliquely angled fan blades on the inner surface of said rim; a plurality of hollow bolts securing said rim to the rotor head; a dome projecting upwardly from the dished upper surface of the rotor; and a bowl mounted on the upper portion of said dome to receive molten material deposited thereon and having apertures arranged to direct the molten material onto the rotor upper surface in a plurality of individual streams.

8. A rotor for use in a fiberizing apparatus comprising a rotatably mounted base, a rotor head of metal mounted on and spaced above said base and having a peripheral wall of substantial depth, there being air channels in the interior of said head extending to said peripheral wall, and a band-like rim connected in spaced relationship with the peripheral wall of the rotor head for rotation therewith, there being an air circulating space of substantial depth between said rim and rotor periphery with which said air ducts communicate.

9. In a fiberizing apparatus a rotatably mounted base, a rotor head mounted on an spaced above said base to provide a cooling space therebetween, said rotor also having interior air channels and having a peripheral wall of substantial depth, the mounting for said head including spacing members between said base and rotor head having peripheral projections forming fan blades when the rotor is in operation, and a band-like rim surrounding the periphery of said rotor head and rotatable therewith, there being an annular space between said rim and the periphery of the rotor head with which the interior air channels of the rotor head communicate.

10. In a fiberizing apparatus including a delivery member for molten material leading from a melting furnace and having a lower discharge end, a metal rotor structure comprising: a base rotatably mounted below the lower discharge end of said delivery member; a cylindrical rotor head mounted on and spaced above said base, said rotor head having a plurality of cooling air channels therethrough and having a dished molten material receiving upper surface; an annular rim surrounding said rotor head, there being an annular space therebetween; a plurality of spaced obliquely angled fan blades on the inner surface of said rim in said annular space; and a plurality of bolts securing said rim to the rotor head.

References Cited in the tile of this patent UNITED STATES PATENTS 2,192,944 Thomas Mar. 12, 1940 2,603,833 Stalego et al. July 22, 1952 2,609,566 Slayter et a1 Sept. 9, 1952 2,624,912 Heymes et a1. Jan. 13, 1953 2,784,451 Bowen Mar. 12, 1957 2,839,782 Tillotson June 24, 1958 FOREIGN PATENTS 751,261 Great Britain June 27, 1956 753,378 Great Britain July 25, 1956 788,491 Great Britain Jan. 2, 1958 

